Switch blade with straight sided stiff tongue and arcuate sided bowed flexible tongue



June 10, 1969 w. R. BAUER 3,449,534

SWITCH BLADE WITH STRAIGHT SIDED STIFF TONGUE AND ARCUATE swan BOWED FLEXIBLE TONGUE Original Filed March a, 1967 Sheet of s FIG-l 86 iG-H FF -2 58 6g 7? Fig-I3 32 INVENTOR. WER NE R R. BAUER HIS ATTORNEYS June 10, 1969 w. R. BAUER 3,449,534

SWITCH BLADE WITH STRAIGHT SIDED STIFF TONGUE AND ARCUATE SIDED BOWED FLEXIBLE TONGUE Original Filed March a, 1967 Sheet 2 of s 24 54. 55 22 78 FEG 3 1:

INVENTOR. WERNER R. BAUER HIS ATTORNEYS June 10, 1969 w. R. BAUER 3,449,534 SWITCH BLADE WITH STRAIGHT SIDED STIFF TONGUE AND ARCUATE SIDED BOWED FLEXIBLE TONGUE Original Filed March a, 1967 Sheet :3 or s FIG-2 I78 I40 37 |9O I510] I28 us I22 H6 ma? fg g q: |94 I IIZ I22 3; 7 I26 I90 V W I96 H8 iue f I48 I4 I s52 :30 f 44 I22 "II I49 n5 I20 I49 I68 I66 I58 I70 I82 H930 I56 United States Patent 3,449,534 SWITCH BLADE WITH STRAIGHT SIDED STIFF TONGUE AND ARCUATE SIDED BOWED FLEXIBLE TONGUE Werner Robert Bauer, Radnor, Pa., assignor to Robertshaw Controls Company, Richmond, Va., a corporation of Delaware Continuation of application Ser. No. 642,614, Mar. 8, 1967. This application June 26, 1968, Ser. No. 742,979 Int. Cl. H01h 15/18 US. Cl. 200-67 11 Claims ABSTRACT OF THE DISCLOSURE This application discloses a switch construction having a flexible snap switch blade with opposite inward tongues connected to the ends of the blade. One of the tongues is a relatively flexible longitudinally arcuate sided tongue and the other is a relatively stiff, longitudinally parallel sided tongue. The tongues engage opposite notches in a central rod. These members are mounted in aswitch cavity of a casing from which an actuating plunger and electrical connectors extend. The switch construction may be made of very small size and relatively large current carrying capacity.

This application is a continuation of application Ser. No. 642,614, filed Mar. 8, 1967, and is a continuation-inpart of copending parent application Ser. No. 431,107, filed Feb. 8, 1965, both now abandoned.

This invention relates to la flexible flat sheet metal blade switch.

The blade of the switch may be an entirely flat ridgeless snap action sheet metal flexible blade entirely free of relatively sharp right angle stiflening bends or ridges, and having outer ribbon shaped tension members joined integrally with blade end cross members. Such blade may have an inward relatively flexible longitudinally arcuate edged snap tongue, and a relatively stiff longitudinally parallel edged pivot tongue. The cooperation of these two tongues during the snap action of the blade is such that much less force is required to actuate the blade past the snapping zone than is required with a substantially parallel sided flexible tongue.

Said blade may have its substantially parallel sided relatively stiff unperforated compression tongue integrally joined to one of said end cross members and extending and terminating in a straight transverse inner end which rocks or pivots in -a straight notch in a straight pivot rod of the switch.

The blade may also have its relatively flexible compression tongue integrally joined to the other of said end cross members and extending inwardly and terminating in a straight transverse inner end which rocks on another notch on the other side of such pivot rod.

Said flexible compression tongue is so shaped that it produces a much more evenly distributed stress throughout the length of such flexible tongue. For this purpose, the flexible tongue is provided with arcuate longitudinal edges. These arcuate edges may be symmetrical with respect to each other, and may also be convex or concave with respect to each other.

The stress distribution throughout such flexible arcuate sided flexible tongue is such that there is a much less flexing force needed to snap the switch blade past the snap point than is required with a substantially parallel sided compression flexible member.

The switch blade and pivot rod may be encased with other switch parts in a suitable casing with an outwardly extending actuating plunger for the blade.

The switch construction may be made of surprisingly 3,449,534 Patented June 10, 1969 small size and surprisingly large current carrying capacity.

Other advantages are apparent from this description, the appended claimed subject matter, and/or the accompanying drawing in which:

FIGURE 1 is a cross section of a switch embodying this invention taken along the line 11 of FIGURE 2.

FIGURE 2 is a cross section of FIGURE 1, taken along the line 2-2 of FIGURE 1.

FIGURE 3 is a cross section taken along the line 3-3 of FIGURE 2.

FIGURE 3A is a view similar to FIGURE 3, but showing a modification of the casing and flat metal pivot rod.

FIGURE 4 is a figure similar to FIGURE 1 with the parts shown in actuated position in dotted lines.

FIGURE 5 is an enlarged cross-section of the flat metal pivot rod in engagement with the inner ends of the blade tongues.

FIGURE 6 is a cross section along the line 6-6 of FIGURE 5.

FIGURE 7 is a cross section along the line 77 of FIGURE 6.

FIGURE 8 is an enlarged cross section of the contact members before the start of actuating movement.

FIGURE 9 is a view similar to FIGURE 8 showing the contact members after the start of the actuating movement, but before the snap action.

FIGURES 10-12 are diagrammatic progressive illustrations of the downward snap action of the switch of FIGURE 1.

FIGURES l3 and 14 are similar to FIGURES 10l2, but showing the upward return movement.

FIGURES 15 and 16 are plan views of other embodiments of blade constructions.

FIGURE 17 is a cross section similar to FIGURE 1 but showing a modified casing construction and modified tongue and rod engagement.

FIGURES 1821 are diagrammatic progressive illustrations of the upward snap action of the switch of FIG- URE 17.

FIGURES 22 and 23 are similar to FIGURES 18-21, but showing the downward snap action.

FIGURES 24 and 25 are diagrammatic illustrations of the application of the blade construction of FIGURES l-7 to the handle actuation of FIGURE 17, with a return spring actuation added.

FIGURES 26 and 27 are respectively top plan and side elevation views of the outer walls of a very small switch made according to this invention, the views being drawn to actual scale in the application drawing.

FIGURE 28 is a vertical cross section, in greatly enlarged scale, of the switch of FIGURES 26 and 27, and taken along the line 28-28 of FIGURE 26.

FIGURE 29 is a cross section taken along the line 2929 of FIGURE 28, said FIGURE 29 being rotated 90 with respect to FIGURE 28.

FIGURE 30 is a top view of the switch blade of FIG- URES 28 and 29, with the movable contacts removed.

FIGURE 31 is a view similar to FIGURE 30 but showing a slightly modified embodiment.

FIGURE 32 is a side elevation of the switch blade of FIGURE 30 or 31, with the movable contacts added.

FIGURE 33 is a perspective view of the switch blade and supporting rod of FIGURES 28 and 29.

FIGURE 34 is a cross section along the line 3434 of FIGURE 28 in reduced scale.

Certain words indicating direction, relative position, and the like, are used in the specification and claims for the sake of brevity and clearness of description. However, it is to be understood that such words are used only in connection with the illustrations in the drawings, and that the parts of the actual embodiments, when in use, may have entirely different directions, relative posi- 3 tions, and the like. Examples of such words are vertical, horizontal, upper, lower, etc.

A switch, such as is illustrated in FIGURES l9, may have an insulative casing having an insulative wall or wall construction including opposite casing sides or side walls 12 and 14, FIGURE 3, opposite casing ends or end walls 16 and 18, FIGURES 1 and 2, a casing bottom or bottom wall 20, and a casing cover or cover wall 22. The casing cover 22 may be detachably secured by bolts 24 which may be at the corners of the casing. These walls form a switch cavity 26 which may be covered and uncovered by means of the cover or cover wall 22.

Before the cover 22 is placed over the switch cavity 26, a switch construction 28 may be placed in the cavity 26 in such a manner that the switch parts are properly secured in the cavity 26 by the covering action of cover 22.

Such switch construction 28 may include a rigid, flat, metal, electrically conductive rod 30, a snap action, sheet metal blade 32, a pair of stop members 34 and 36, one or both of which may be connected to an electrical conductor, such as 38 and/or 40, which may extend out through the insulative casing wall. Either or both of said stop members 34 and/or 36 may be an electrically conductive contact member.

The blade 32 of this invention has many advantages, which include:

(a) The previously described cooperation of the relatively flexible, arcuate sided tongue with relatively stiff, substantially parallel sided tongue.

(b) Rocking movement of its contact 42 before and after the snap action.

(c) Wiping action of the contacts before and after the snap action.

((1) Relatively large range of overtravel is permitted, if desired.

(e) A single blade construction is provided which per- 'rnits easy assembly, as will become apparent.

(f) The cost of production is greatly reduced.

(g) No additional snap-spring construction is required.

(h) The blade may be telescoped or threaded on the "pivot rod to produce a sub-assembly which may be unitarily mounted in the cavity 26 of the casing 10.

The rigid rod 30 may extend outside of the casing 10, with the rod 30 passing through the casing wall 14. The rod 30 may have an electrical conductor receiving end 44, to which an electrical conductor may be secured by means of the opening 46. The rod 30 may be inserted in a slot 48, FIGURE 1, in the side wall 14, as indicated by the dotted lines 48, FIGURE 3. This portion of the rod 30 may have a notch which engages a corresponding notch in the wall 14, so that the rod 30 cannot be moved leftward, in FIGURE 3. The other end 52 of the rod 30 may enter an opening in the casing side wall 12, in such a manner that the rod 30 cannot move rightward in FIGURE 3 because of the opening in the wall 12. A suitable slot 53, FIGURE 1, may be provided in the wall 12, to receive the rod end 52, and also an insulative slab 54, which is held by a suitable notch 55 in the cover 22 and also in a notch in the end 52 of the rod 30. It is to be noted that the right portion of the rod 30 which is shown in FIGURE 3 is relatively narrow, so that the blade 32 may be placed around the central portion of the rod 30 before such rod 30 and blade 32 are placed in the casing 10.

It is to be seen that the blade 32 and the rod 30 may be telescoped or threaded with respect to each other over the right end of the rod 30, FIGURE 3, and then such assembled rod and switch blade may be placed in the casing 10, before the cover 22 is placed thereon. Thereafter, the slab 54 may be placed therein, if used, and then the cover 22 may be placed over the side walls of the casing, as shown in FIGURE 3 and bolted thereon. This secures the rod 30 and the switch blade 32 in position within the cavity 26 of the casing 10.

The rod 30, FIGURES 5-7, has two opposite flat sides 57 and 59 and two opposite narrow edges 60 and 62, and has two straight continuous transverse tongue end receiving notches 56 and 58, said notches extending completely across said flat sides.

The snap action, sheet metal blade 32 may be an entirely flat, ridgeless snap action blade which is entirely free of relatively sharp, substantially right angle bends and has two outer parallel tension ribbon shaped members 64 and 66 joined integrally and in the same plane with two flat blade end cross members 68 and 70. The blade 32 also has a relatively stilI unpunctured compression tongue 72 integrally joined with the cross member 68 and extending inwardly and terminating in a continuously straight transverse pivot end 74, FIGURE 6, which is engaged and pivots in and substantially coextensive with one of the notches 58 of the rod 30. Lateral side movement locking means may be provided in the form of fork extensions 76 at respective ends of said continuously straight transverse end, said tongue 72 having parallel, unbent sides substantially throughout the major portion of the length of said tongue. Said fork extensions 76 straddle the rod edges 60 and 62, as shown in FIG- URE 6.

The blade 32 also has a relatively flexible bowed compression tongue 78 which is joined integrally to the other of the cross members 70 and extends inwardly and terminates in a straight transverse pivot end 80, FIGURE 6, which is engaged and pivots in the other of the notches 56 of the rod 30. The average width of the tongue 78 may be made less than the average width of the tongue 72 by making the side edges 82 of the tongue 78 longitudinally arcuate shaped or arcuate sided, whereas the sides 84 of the tongue 72 may be made longitudinally parallel and relatively straight throughout its major longitudinal extent.

The ridgeless flexible blade 32 which is provided with the inward, relatively flexible, longitudinally arcuate edged snap tongue 78, and the relatively stiff longitudinally parallel edged pivot tongue 72, has great advantage. Such blade 32 requires much less force to actuate the blade past the napping zone than is required when the blade is provided with a flexible snap tongue that has parallel sided flexible tongue edges.

This is so because the flexible snap tongue 78 with its arcuate sides or edges 82, 82, FIGURES 2 and 6, has a much more uniform or flatter stress distribution along the length of the tongue than is present in the parallel sided flexible snap tongue of the prior art, which has a much steeper and higher domed stress distribution along the length of such parallel sided tongue.

The reduced force required for snapping applicants arcuate flexible tongue 78 is very advantageous as compared to the force required for snapping the parallel sided flexible tongue of the prior art. The switch has greater sensitivity. The switch parts do not wear out as fast. The switch can be made much smaller. Many other advantages are present.

The pair of stop members 34 and 36, FIGURES 1 and 2, straddle the cross member 70 and its contact member 42 between which the blade 32 snaps to opposite positions, as indicated in FIGURES 1 and 4. A previously stated one or both of the members 34 or 36 may be a contact member with conductor flat rods 38 and/or 40, which may be placed in suitable notches or slots in the end wall 16 of the casing and may be held in place by suitable enlargements in the width of the conductors 38 and/or 40, not shown, so that these conductors may be held in place by the cover 22, after the cover has been blotted in place.

If desired, an actuating blade 86 may be pivoted in an opening 88, diagrammatically shown in the side 12 of thecasing. The specific construction of the blade 86 and opening 88 may .be substantially as shown in the patent to Besemer, No. 3,040,152, patented June 19, 1962.

The blade 86 may be manually operated and may actuate a switch blade pushing pin 90 which engages the end or cross member 68 of the switch blade 32. The pin 90 may be enlarged at 92, so that such enlargement 92 prevents or limits the upward movement of the pin 90. If desired, a stopping member or screw 94 may be provided in the wall 14, to be engaged by the cross member 68 of the blade 32, and thus limit the downward movement in FIGURE 1 of the cross member 68. If desired, a lock nut 96 may be provided to hold the pin 94 in the selected adjusted position.

FIGURES 8 and 9 show the advantages of the spherical or concave surface of the movable contacts 42 and how the switch movement caused by initial downward movement of the pin 90 before the blade 32 reaches its snapping position may cause the contacts 42 to slide with respect to the contact 34, this movement also being indicated in FIGURE 4. FIGURE 9 shows the travel leftward as the end 68 of the blade is pushed down and before the snap action takes place. This rocking and sliding action maintains the contact surfaces in a clean condition and an electrically conducting condition.

FIGURES 10, 11, and 12 are diagrammatic views showing how the contact 42 remains against the stationary contact 34 until after the tension members 64 pass the notch 56. A construction in which the notch 56 is above the notch 58 would cause the switch to return to the position of FIGURE automatically, unless the tension members are allowed to be pushed down below the notch 58, as shown in FIGURE 12. Under these conditions, the switch construction may remain in the down position, until it is manually pushed up, or is pushed up by the action of a compression spring 65 which may be placed under the cross member 68, in a manner somewhat similar to that shown in FIGURES 24 and 25. Such spring 65 may be omitted, however, if the screw 94 of FIGURE 1 is adjusted so the blade 32 cannot be pushed down as far as shown in FIGURE 12.

FIGURES 13 and 14 show how the switch construction may be snapped from a low position to a high position, if no spring 65 is provided, with the corresponding movement of the movable contact 42 by causing the tension member 64 or tension line to cross the notch position 56.

However, it is to be understood that it is not the actual tension members that determine the exact snapping point, but rather the tension and compression lines which are produced by the various members, which approximate the position above described. However, there is a definite snapping point very near the positions which have been described, although they may not be exactly at such points.

In FIGURE 17, the casing 98 is shown which may be, in general, the same as casing 10 of FIGURES l, 2 and 4, but with the side and end walls not as irreguar in cross section. The rod and the blade 32' and the contacts 34, 36 and 42 may be, if desired, substantially identical with those heretofore described in connection with the previous FIGURES 1-9. However, the left end of the blade 32' may be provided with a handle 100, which may extend through a slot 102 in the casing wall. The left end of the blade 32' may be actuated manually by an operators finger which may push the handle 100 in either direction, as is readily obvious from such FIGURE 17.

However, the tongues 72' and 78' of FIGURE 17 have their inner ends engaging notches 58 and 56' which are substantially equally opposite each other, along the length of pivot rod 30, so that the forces are applied to the rod 30 at exactly opposite positions. Under these conditions, the blade 32 of FIGURE 17 will remain in the position to which the blade 32' is snapped. That is, if the user snaps the blade 32 down to the lower position, as shown in FIGURE 17, the blade will remain there until he pushes it up to the upper position, and vice versa. This is illustrated in FIGURES 18 and 23, which progressively illustrate the fact that the handle 100 may cause the contact 42 to move from stationary contact 36 to stationary contact 34 by upward movement of the handle as is in FIGURES 18-21 and will remain at the position shown in FIGURES 20, 21, to which it is moved. FIG- URES 22, 23 show how the handle 100 will cause the contact 42 to move downwardy and to remain in the down position of FIGURE 23 until the user selects to move the handle 100 up.

FIGURE 15 shows a modified embodiment in a blade 32". In this blade, the stifi tongue 72 may be substantially the same as in the previous figures. However, the flexible tongue 78" has it sides 82" arced inwardly, instead of outwardly as in the previous embodiment. This construction will cause the tongue 78" to impart a greater rocking action on the contact 42 because the area at 104 between the tongue 78" and the crosspiece 70 is stiffer than in the embodiment of FIGURE 2.

In the embodiment of FIGURE 16, the stiff tongue 72" is attached to the crosspiece 70, which carries the contact 42, and the flexible tongue 78" is attached to the crosspiece 68. Many of the advantages of all of the embodiments previously described are also provided in this modified embodiment shown in FIGURE 16.

In FIGURE 4, the tongues 72 and 78 are shown with their inner edges opposite each other, corresponding to the positions of the inner edges of the embodiments of FIGURES 17-23. If the edges of the tongues of FIG- URE 4 are placed as in such FIGURES 17-23, then a spring similar to spring 65 of FIGURES 12, 24 and 25 may be added, as shown in dotted lines in FIGURE 4, which may be placed around the screw 94 with one end engaging the wall 14 and the other end engaging the cross member 68. This will cause the blade 32 and plunger 90 of FIGURE 4 to be upwardly biased to move to their upper positions when the actuating blade 86 is released.

The embodiments of FIGURES 17-23 may be biased in upward or downward directions by providing a spring similar to spring 65 either above or below the left cross member of the blade 32', if desired. Such spring will cause the switch to be biased to return to upward or downward position when released, as is obvious.

FIGURES 26-32 show an extremely small snap switch which has a surprisingly high current capacity. FIGURES 26 and 27 are top and side views of the outside of the switch casing drawn to scale. The actual dimensions for FIG. 26 are .190 x .385 inch and for FIG. 27 are .260 x .385 inch. The weight is .57 gram.

Such switch may have an insulative casing having an insulative wall or wall construction including two opposite sides or side walls 112 and 114, two opposite end walls 116 and 118, and a bottom wall 120. These walls may be integrally joined together to form a switch cavity 126 which may be closed by a flat cover 122.

The walls 112, 114, 116, 118 may be covered and uncovered by means of the cover 122. The cover 122 may be secured to the walls 112, 114, 116 and 118- by any suitable means, such as by adhesive means, fasteners, and the like.

Before the cover 122 is placed over the cavity 126, a switch construction 128 is placed in the cavity 127 in such a manner that the switch parts are properly secured in the cavity 126 by the covering action of the cover 122.

The switch construction 128 may include a rigid, straight, flat metal electrically conductive rod 130 with opposite relatively wide flat sides 132 and 134 and opposite relatively narrow edges 136 and 138.

The rod 130 may be embedded in preformed notches 140 and 142 in the opposite side walls 112 and 114 and extends out of the side wall 114, which wall 114 is relatively thick relatively to the walls 112, 116 and 118. Suitable screw mounting holes 144 may extend through the wall 114 for mounting the switch on a support panel and the like. A suitable electrical conductor 7 receiving opening 130 is provided for attaching an electrical conductor, if desired. The rod .130 has opposite tongue end receiving notches 137 and 139.

An electrical conductor bar 148 extends out of and is embedded in the side wall 114 and has an inward stationary contact first elbow 150 extending into the switch cavity 126. Another electrical conductor bar 152 extends out of and is embedded in and extends out of the side wall 114 and has a second elbow 154 spaced from the first elbow 150. These bars 148 and 152 may be embedded in preformed notches in Wall 114, as shown in FIGURE 34 and have shoulders 149 to lock them in place.

A snap action sheet metal blade 156, somewhat similar to blade 32, has outer flat ribbon-shaped tension members 158 and 160 and opposite end cross members 162 and 164 joined integrally with the tension members 158- and 160.

The tension members 158 and 160 extend past and outside the rod edges 136 and 138'.

The blade 156 has an inward, relatively flexible, snap tongue 166 with its tongue end 168 integrally connected to the blade end cross member 164 and with its other tongue end 170 engaging the rod notch 137.

The blade 156 also has an inward relatively stilf pivot tongue 172 with one pivot tongue end 174 integrally connected to the other blade end cross member 162. The other pivot tongue end engages the other rod notch 139.

The blade 156 also has convex surfaced movable contact members 178 and 180 on the blade end cross member 164 which alternately engage the stationary contact elbows 150 and 154.

The flexible snap tongue 166 has opposite longitudinally arcuate edges 182 and 184. The stiff pivot tongue 172 has opposite longitudinally parallel edges 186 and 188. These tongues 166 and 172 have all of the characteristics and advantages heretofore described.

As shown mainly in FIGURES 30, 32 and 33 the snap action sheet metal blade 156, when it is in an unassembled and unflexed condition, as shown in FIGURES 30 and 32, is entirely free of relatively sharp right angle bends, has two outer parallel ribbon shaped tension members 158 and 160, joined integrally and in the same plane with two flat end cross members 162 and 164. The blade also has a flat, relatively stiff, compression tongue 172 with straight parallel unbent edges 186 and 188- and is integrally joined at 174 at a relatively small angle, as shown in FIGURE 32, to the cross member 162. This tongue 172 extends inwardly and terminates in a straight transverse notch engaging pivot end 176. Such blade 156 also has another relatively flexible compression bowed tongue 166 integrally joined to the other 164 of such cross members at 168 and at a relatively small angle. The blade 166 has longitudinally symmetrically arcuate side edges 182 and 184 and terminates in a straight transverse notch engaging pivot end 170'.

The snap action sheet metal blade 156 is assembled over the rod 130 with the two tension members 158 and 160 and the two end cross members 162 and 164 surrounding the rod 130, as shown in FIGURE 33, and with the transverse notch engaging pivot ends 170 and 176 engaging respective ones of the tongue and receiving notches 137 and 139, as shown in FIGURE 28.

A pair of stationary stop members 150* and 154 are alternately engaged by the cross member 164 when the blade 156 snaps to opposite positions. One or both of the members 150' and 154 may be electrical contact members with conductor ends extending out of the insulative casing wall. The plunger 190 extends outside of the casing, and engages the other 162 of the cross members to reciprocate the blade.

A plunger 190 engages the blade end cross member 1.62 and extends out of the side wall 112. The plunger has an enlargement or Ebead 192 to provide suitable enlarged contact with the cross member 162 and the side wall 112. The plunger 190 may be of any desired cross section, such as square, round, or the like.

A compression leaf spring 194 may be V-shaped with one end engaging the cross member 162 and the other end engaging a notch 196 in the wall 114. The spring 194 returns the blade to its upper position in FIGURE 28 after the blade has been pushed down by the plunger 190 and then released.

The blade 156 snaps down when the plunger is pushed down in a manner similar to the blades 32 and 32 heretofore described.

The notches 137 and 139 are not as wide as the rod 132 and have end shoulders 198 for preventing undue sidewise displacement of the blade .156.

The blade 156A of FIGURE 31 is substantially similar to the blade 156 of FIGURE 30. The blades 156A and 156 may be used in the same switch construction of FIGURES 26-29, 33 and 34. The main difference between the blades 156 and 156A is that the tension ribbon members 158A and 160A remain of uniform thickness for a greater length than the ribbon members 158 and 160'. Otherwise the two blades 156 and 156A are substantially the same.

The holes 144 may be used to receive mounting screws, as previously described. Such holes may be threaded, as shown, or unthreaded, if desired. The holes may be countersunk at .145 at one end to receive countersunk screw heads.

Alternatively, the holes 144 may receive screws that fasten the cover 122 to one end of the wall 114 and hold the cover 122 against the adjacent ends of walls 112, 116 and 118.

Also, the switch may be simultaneously covered and mounted on a panel and the like by screws or bolts passing through holes 144 and being screwed or bolted on the panel as desired. This simultaneously secures the cover 122 to the walls 112, 114, 116 and 118, and the casing to the panel and the like.

While the form of the invention now preferred has been disclosed, as required by statute, other forms may be used, all coming within the scope of the claimed subject matter.

A new, useful and unobvious switch construction has thus been provided by this invention.

What is claimed is:

1. A' snap acting switch comprising:

a switch casing having a switch cavity and an electrically insulative casing wall;

a rigid flat metal, electrically conductive rod having an electrical conductor receiving end outside said casing and a straight portion extending through said casing wall into said switch cavity, said rod being unperforated and unbent in said casing and having two opposite straight flat sides and two opposite narrow edges and with two straight transverse tongue and receiving notches respectively on said opposite flat sides;

a snap action sheet metal flexible blade entirely free of relatively sharp right angle bends in said switch cavity, having two outer parallel ribbon shaped tension members joined integrally and in the same plane with two flat freely movable blade and cross members, said blade having a parallel sided, relatively stifi, unperforated compression tongue integrally joined to one of said cross members and extending inwardly and terminating in a straight transverse pivot end in one of said notches, said tongue having parallel unbent sides substantially throughout the major portion of the length of said tongue, said blade having another relatively flexible compression bowed snap tongue integrally joined to the other of said cross members and extending inwardly and terminating in a straight transverse pivot end in the other of said notches, said flexible compression tongue having longitudinally symmetrically arcuate side edge, said tension members, said blade end cross members, said stiff compression tongue, said flexible snap tongue all being integrally joined together so that they can flexibly bend respectively to each other where they are joined together during snap operation of said blade;

a pair of stop members straddling and being alternately engaged by one of said cross members when said blade snaps to opposite positions, and one of said stop members being an electrical con-tact member with a conductor extending out of said insulative casing wall;

and means for reciprocating the other of said cross members.

2. A switch according to claim 1 in which said arcuate edges are concave toward each other.

3. A switch according to claim 1 in which said arcuate edges are convex toward each other.

4. A snap acting switch comprising:

a conductive pivot rod having two opposite flat sides and two opposite narrow rod edges and with two straight transverse tongue end receiving rod notches respectively on said opposite flat sides;

an entirely flat, ridgeless snap action sheet metal blade entirely free of relatively sharp stiflening ridges and having outer flat ribbon shaped tension members joined integrally and entirely in the same plane with two flat opposite blade end cross members, said tension members passing outside said rod edges, said blade having an inward relatively flexible longitudinally areuate edged compression bowed snap tongue with one tongue end integrally connected to one of said blade end cross members and its other tongue end engaging and pivoting in one of said rod notches, said blade having an inward relatively stiff unperforated parallel edged pivot tongue with one pivot tongue end integrally connected to the other blade end cross member and with its other pivot tongue end engaging and pivoting in the other of said rod notches, said tension members, said blade end cross members, said stiff compression tongue, said flexible snap tongue all being integrally joined together so that they can flexibly bend respectively to each other where they are joined together during snap operation of said blade;

convex surfaced movable contact members on a first named one of said blade end cross members;

stationary contact members alternately engaged by said movable contact members;

and means for moving the second named one of said blade end cross members.

*5. A snap switch according to claim 4 in which said areuate edges are concave with respect to each other.

6. A snap switch according to claim *5 in which said areuate edges are convex with respect to each other.

7. A snap acting switch comprising:

a switch casing having a switch cavity and an electrically insulative casing wall;

a rigid, flat metal, electrically conductive rod having an electrical conductor receiving end outside said casing, extending through said casing wall into said switch cavity, and having a straight portion inside said cavity with two opposite flat sides and two opposite narrow edges and two straight transverse tongue end receiving notches respectively on said opposite flat sides;

a snap action sheet metal blade which, when it is in unassembled and unflexed condition, is entirely free of relatively sharp right angle bends, has two outer parallel ribbon shaped tension members joined integrally and in the same plane with two freely movable flat end cross members, said blade also having a flat, relatively stiff, compression tongue with straight parallel unbent edges and integrally joined at a relatively small angle to one of said cross members and extending inwardly and terminating in a straight transverse notch engaging pivot end, said blade also having another relatively flexible compression bowed snap tongue integrally joined to the other of said cross members at a relatively small angle, having longitudinally symmetrically areuate side edges and terminating in a straight transverse notch engaging pivot end, said tension members, said blade end cross members, said stiff compression tongue, said flexible snap tongue all being integrally joined together so that they can flexibly bend respectively to each other where they are joined together during snap operation of said blade;

said snap action sheet metal blade being assembled over said rod with said two tension members and said two end cross members surrounding said rod, and with said transverse notch engaging pivot ends engaging respective ones of said tongue end receiving notches;

a pair of stationary stop members straddling and being alternately engaged by one of said cross members when said blade snaps to opposite positions, and at least one of said stop members being an electrical contact member with a conductor end extending out of said insulative casing wall;

and reciprocating means extending outside said casing for reciprocating the other of said cross members.

8. A combination according to claim 7 in which said blade has convex surfaced movable contact members which alternately engage said stationary stop members.

9. A combination according to claim 7 in which said reciprocating means is a plunger engaging said other of said cross members and extending out from said cavity through said insulative wall.

-10. A combination according to claim 7 in which said casing has opposite casing side walls, opposite casing end walls, a casing bottom wall forming said switch cavity with said conductive rod passing through one of said side walls and with the inner end of said rod in a slot in the other of said side walls.

11. A combination according to claim 10 in which a cover is provided for said casing end walls and side walls with means for locking said rod against longitudinal and sidewise movement.

References Cited UNITED STATES PATENTS 2,565,790 8/1951 Van Ryan et al. 2,927,171 3/ 1960 Rhodes. 2,980,774 4/ 1961 Millerwise. 3,244,848 4/ 1966 Chapin et al.

FOREIGN PATENTS 642,609 6/1962 Canada.

ROBERT K. SCI-IAEFER, Primary Examiner.

D. SMITH, JR., Assistant Examiner. 

